Afghan bomber attacks near major US base near Pakistan border, killing 4

The policewoman, identified as Sgt. Nargas, shot Joseph Griffin, of Mansfield, Georgia, on Monday, in the first such shooting by a woman in the spate of insider attacks. Nargas walked into a heavily-guarded compound in the heart of Kabul, confronted Griffin and shot him once with her pistol.

The US-based security firm DynCorp International said on its website that Griffin was a US military veteran who earlier worked with law enforcement agencies in the United States. In Kabul, he was under contract to the NATO military command to advise the Afghan police force.

The ministry spokesman, Sediq Sediqi, told a news conference that Nargas, who uses one name like many in the country, was born in Tehran, where she married an Afghan. She moved to the country 10 years ago, after her husband obtained fake documents enabling her to live and work there.

A mother of four in her early 30s, she joined the police five years ago, held various positions and had a clean record, he said. Sediqi produced an Iranian passport that he said was found at her home.

No militant group has claimed responsibility for the killing.

The chief investigator of the case, Police Gen. Mohammad Zahir, said that during interrogation, the policewoman said she had plans to kill either the Kabul governor, city police chief or Zahir himself, but when she realized that penetrating the last security cordons to reach them would be too difficult, she saw "a foreigner" and turned her weapon on him.

There have been 60 insider attacks this year against foreign military and civilian personnel, compared to 21 in 2011. This surge presents another looming security issue as NATO prepares to pull out almost all of its forces by 2014, putting the war against the Taliban and other militant groups largely in the hands of the Afghans.

More than 50 Afghan members of the government's security forces also have died this year in attacks by their own colleagues. The Taliban claims such incidents reflect a growing popular opposition to the foreign military presence and the Kabul government.